Cause Of Decline Research Articles

How pollinator dependence may mediate farmer adoption of pollinator supporting practices and perceptions: a case study from western France

There is limited knowledge on why farmers adopt pollinator-supporting practices, which is crucial to stimulate their adoption. The dependence of farmers on pollination may influence their perception of pollinators and their willingness to adopt these practices. We addressed why farmers adopt pollinator-supporting practices using a 2011 survey conducted within a cereal plain in western France, where farmers were moderately dependent on pollination for crops like oilseed rape and sunflower. We assessed the factors influencing the adoption of practices to promote pollination, including pollination dependence. We found no effect for pollination dependence. Conversely, we found that farm size, pesticide use, advisory services and the perception of costs decreased the willingness to adopt, while older farmers were more incline to adopt. We also evaluated perceptions related to pollinators: more than 85% of farmers considered bees important for crop production and recognized pesticides as a major cause of decline. We found no effect of pollination dependence on farmers’ perceptions. Compared to similar studies over the past decade, we found similarities, particularly regarding pollinator-related perceptions. Finally, we compared the willingness to adopt in 2011 with the actual adoption in 2024, showing that there has been little change. This raises questions on the pathways to promote the adoption of pollinator-supporting practices to ensure for the future of pollinator conservation.

Taking the Pulse of Resilience in Conserving Seagrass Meadows.

Foundational habitats such as seagrasses and coral reefs are at severe risk globally from climate warming. Infectious disease associated with warming events is both a cause of decline and an indicator of stress in both habitats. Since new approaches are needed to detect refugia and design climate-smart networks of marine protected areas, we test the hypothesis that the health of eelgrass (Zostera marina) in temperate ecosystems can serve as a proxy indicative of higher resilience and help pinpoint refugia. Eelgrass meadows worldwide are at risk from environmental stressors, including climate warming and disease. Disease outbreaks of Labyrinthula zosterae are associated with recent, widespread declines in eelgrass meadows throughout the San Juan Islands, Washington, USA. Machine language learning, drone surveys, and molecular diagnostics reveal climate impacts on seagrass wasting disease prevalence (proportion of infected individuals) and severity (proportion of infected leaf area) from San Diego, California, to Alaska. Given that warmer temperatures favor many pathogens such as L. zosterae, we hypothesize that absent or low disease severity in meadows could indicate eelgrass resilience to climate and pathogenic stressors. Regional surveys showed the San Juan Islands as a hotspot for both high disease prevalence and severity, and surveys throughout the Northeast Pacific indicated higher prevalence and severity in intertidal, rather than subtidal, meadows. Further, among sites with eelgrass declines, losses were more pronounced at sites with shallower eelgrass meadows. We suggest that deeper meadows with the lowest disease severity will be refuges from future warming and pathogenic stressors in the Northeast Pacific. Disease monitoring may be a useful conservation approach for marine foundation species, as low or absent disease severity can pinpoint resilient refugia that should be prioritized for future conservation efforts. Even in declining or at-risk habitats, disease surveys can help identify meadows that may contain especially resilient individuals for future restoration efforts. Our approach of using disease as a pulse point for eelgrass resilience to multiple stressors could be applied to other habitats such as coral reefs to inform conservation and management decisions.

Influence of agricultural intensification on pollinator pesticide exposure, food acquisition and diversity

Abstract Pollinators are essential for maintaining sustainable crop production, while the decline of pollinators is a widespread concern. Agricultural intensification is one of the primary drivers of the decline of insect pollinators. Agricultural intensification usually involves a decreasing of non‐crop semi‐natural habitat and an increasing of pesticide exposure for pollinators. However, causal links between agricultural intensification, increased pesticide exposure, and reduced pollinator's food sources and pollinator diversity remain underexplored. We assessed pollinator diversity across a landscape gradient where the proportion of rice ranged from 11% to 85% in South China. We placed honeybee (Apis mellifera) and mason bee (Osmia excavata) in these landscapes and investigated pesticide exposure in honeybee foragers and pollen, and in mason bee pollen and nesting materials. We also assessed the acquisition of food by mason bees. We found a higher frequency of pesticide detection in honeybee foragers and honeybee pollen samples in areas with a higher proportion of rice fields. There was a strong positive relationship between mason bee food acquisition and the proportion of semi‐natural habitats, while no significant effects of pesticide exposure on pollinator diversity were found in addition to the effect of semi‐natural habitat. Synthesis and applications: Our results suggest that pollinator communities could be at an increased risk of pesticide exposure due to intensified agriculture, while the negative impact on pollinator diversity mainly results from the loss of habitat and/or reduced food sources. This study highlights the importance of conserving semi‐natural habitat to mitigate the causes of decline in pollinator diversity. We also recommend long‐term, multi‐year studies to further understand the mechanisms behind the loss of pollinators in farming landscapes.

Frogs and Toads as Indicators of Ecological Health

Purpose: The purpose of this review was to investigate the causes of decline in frogs and toads population in the environment using systematic literature review methodology. The specific objectives of the study were: to determine the importance of amphibians in the environment, to establish the causes of the decline of amphibians and to suggest strategies that can be put in place to control their decline. Methodology: The systematic literature review methodology was adopted. By combining the literature overview with expert opinion, the researcher was able to crosscheck conclusions from different sources to search for general trends and regularities. Findings: Their decline can be attributed to presence of toxic chemicals (pesticides, accaricides, termicides, fertilizers), too much heat reaching them, or destruction of their habitat, capital development projects that lower water table and environmental conditions, birds, mammals and reptiles that prey on their eggs, habitat loss, diseases like red leg syndrome, harvesting for a variety of reasons, climate change and global warming, and invasive species. Unique Contribution to Theory, Policy and Practice: Suggested strategies for reducing decline are: .using environmentally friendly chemicals and only when very necessary otherwise, organic chemicals should be recommended, restoration of habitats, combating climate change and global warming, reducing water run-off and preventing rubbish, silt and garden waste from getting into storm water drains, constructing and maintaining sediment traps near waterways, especially when disturbing surface vegetation cover, keeping a wide belt of vegetation around water bodies as a buffer zone for contaminants and to control erosion a voiding wearing insect repellents and other lotions if you go swimming in areas where frogs live, no drainage of wetlands, no collection of bush rock, no burning of patches of bush which frogs shelter in and no reduction in the quality of wildlife corridors, which connect areas of frog habitat and proper rules and regulations on the use of wetlands, swampy areas, shorelines and river rines.

Soviet Energy Policy: Lessons for Modern Russia

The study examines the energy strategy and achievements of the Soviet Union in building the world’s largest oil and gas complex (OGC). The paper analyzes the causes of decline in the domestic oil and gas industry after the Soviet era and proposes recommendations for enhancing Russia’s energy policy, considering experiences. Within the framework of the energy policy of the Russian Federation, the author discusses a diverse set of state tasks. These tasks encompass ensuring stable growth in proven reserves, optimizing hydrocarbon resource usage, fostering progress in new oil and gas regions, and developing industry personnel through training programs.

High levels of mislabelling of shark flesh in Australian fish markets and seafood shops

High levels of mislabelling of shark flesh in Australian fish markets and seafood shops

Too Warm and Too Dry—Decline and Threat of the Subarctic-Subalpine Liverwort Hygrobiella laxifolia in a Low Mountain Range in Central Europe under the Conditions of Climate Change

Using the liverwort Hygrobiella laxiflora as an example, this study aims to investigate the impact of climate change on montane species and their ecosystems. The study area is the Elbe Sandstone Mountains in Germany and the Czech Republic, where Hygrobiella laxifolia has an isolated occurrence in deeply carved gorges characterized by a specific microclimate (cellar climate). The focus is on determining the rate at which populations are affected. After little change in the population over a long period, a sudden sharp decline has been observed in recent years. The decline correlates with the mass proliferation of the European spruce bark beetle (Ips typographus) observed since 2017, which has led to a strong thinning of the forests in the area. In many areas of occurrence, the forests now have a much sparser tree layer or none at all. Competition from other, more competitive species also plays an important role as a cause of decline, as these have spread more widely on the sites due to the now higher light levels. The severe bark beetle infestation and the large-scale forest fire of 2022 both represent events that led to the almost complete deforestation of large parts of the study area, which was previously unknown on this scale. Since both the bark beetle infestation and the forest fire are strongly intensified by climate change, we assume that climate change is the main reason for the decline of Hygrobiella laxifolia in the area. The populations of Hygrobiella laxifolia of the Elbe Sandstone Mountains show some morphological peculiarities. As two new species have recently been described within Hygrobiella, we have integrated a sample from the area into a molecular phylogeny of Hygrobiella based on the plastid sequences of trnL-trnF intergenic spacer and matK to clarify the relationships. The sample from Elbe Sandstone Mountains fits well into the clade of Hygrobiella laxifolia.

Effectiveness of population-based recovery actions for threatened southern mountain caribou.

Habitat loss is affecting many species, including the southern mountain caribou (Rangifer tarandus caribou) population in western North America. Over the last half century, this threatened caribou population's range and abundance have dramatically contracted. An integrated population model was used to analyze 51 years (1973-2023) of demographic data from 40 southern mountain caribou subpopulations to assess the effectiveness of population-based recovery actions at increasing population growth. Reducing potential limiting factors on threatened caribou populations offered a rare opportunity to identify the causes of decline and assess methods of recovery. Southern mountain caribou abundance declined by 51% between 1991 and 2023, and 37% of subpopulations were functionally extirpated. Wolf reduction was the only recovery action that consistently increased population growth when applied in isolation, and combinations of wolf reductions with maternal penning or supplemental feeding provided rapid growth but were applied to only four subpopulations. As of 2023, recovery actions have increased the abundance of southern mountain caribou by 52%, compared to a simulation with no interventions. When predation pressure was reduced, rapid population growth was observed, even under contemporary climate change and high levels of habitat loss. Unless predation is reduced, caribou subpopulations will continue to be extirpated well before habitat conservation and restoration can become effective.

The Decline of the Eastern Empire and the Fall of Constantinople: An Omen for Europe?

There is a theory, already outlined by Toynbee, that empires that have succeeded one another in a dominant position are seeing their centre of gravity shift from east to west. This theory has most recently been evoked in connection with the replacement of the European empire by the American empire, which now seems to be giving way to an Asian empire. If we want to analyse historically the mechanisms that lead an empire to its downfall, the best example to choose is undoubtedly that of the Eastern Roman Empire or Byzantine Empire in Western terminology. It is a world that has disappeared, but one that is close enough to us to allow us to understand it, and even to learn from its evolution, which only seems inevitable in retrospect. This story with its succession of internal and external causes of decline is summarized in the present study, leading to the disappearance of the Empire at the hands of the Ottoman dynasty. A parallel is drawn with the present situation of Europe.

Diversity of fishery resources and catch efficiency of fishing gears in the Feni River (Bangladesh)

A thorough examination of fish diversity indices, gear efficiency, catch composition, and decline causes of fish diversity was carried out in the Feni River (Bangladesh). Monthly data collection took place from July to December 2023 at three stations of the river. A total of 8 fish species under 7 orders and 8 families were recorded. The order Perciformes was the most prevalent, representing 30% of the total. Approximately half of the identified species are classified as least concern, while the remaining 4 species are classified as Not Threatened (12.5%), Vulnerable (12.5%), Endangered (12.5%), and Critically Endangered (12.5%). The mean values of the Margalef’s richness (d), Pielou’s evenness (J), Simpson’s index (1-D), Shannon-Weaver diversity (H), and 0.973±0.002 were calculated as follows: 1.720±0.139, 0.699±0.112, and 0.248±0.034, respectively. Based on the Bray-Curtis similarity matrix, two groups were observed at a similarity of 58% within six months across the three sites. The chandi net and ghera net recorded the highest CPUE (kg gear-1day-1) at 5.93±0.966 and 0.53±0.041, respectively. The highest fish catch was recorded in July (2249 ± 668.71 kg), while the lowest was in October (1564 ± 465.05 kg). There was no significant difference (p>0.05) in the monthly fish catch. Fish biodiversity in the Feni River is declining day by day as a result of pollution, overfishing, the use of harmful gear, and a lack of optimal water and pollution. To improve and conserve fish species in the Feni River, it is strongly advised that appropriate fishery management techniques should be applied, that overfishing be closely monitored, and that fishermen be made more aware of their rights.

Ochratoxin A triggers endoplasmic reticulum stress through PERK/NRF2 signaling and DNA damage during early embryonic developmental competence in pigs

Ochratoxin A (OTA), a mycotoxin found in foods, has a deleterious effect on female reproduction owing to its endocrine-disrupting activity mediated through endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) production. However, the mechanisms of OTA-induced ER stress in pig embryos during in vitro culture (IVC) are not yet fully understood. In the present study, porcine embryos were cultured for two days in an IVC medium supplemented with 0.5, 1.0, and 5.0 μM OTA, which led to an OTA-induced reduction in the developmental rate of blastocysts. The mRNA-seq transcriptome analysis revealed that the reduced blastocyst development ability of OTA-exposed porcine embryos was caused by ER stress, ultimately resulting in the accumulation of ROS and the occurrence of apoptosis. The expression levels of some UPR/PERK signaling-related genes (DDIT3, EIF2AK3, EIF2S1, NFE2L2, ATF4, EIF2A, and KEAP1) were found to differ in OTA-exposed pig embryos. OTA induces DNA damage by triggering an increase in RAD51/γ-H2AX levels and suppressing p-NRF2 activity. This effect is mediated through intracellular ROS and superoxide accumulation in the nuclei of porcine embryos. The cytotoxicity of OTA increased the activation of the PERK signal pathways (p-PERK, PERK, p-eIF2α, eIF2α, ATF4, and CHOP) in porcine embryos, with abnormal distribution of the ER observed around the nucleus. Collectively, our findings indicate that ER stress is a major cause of decline in the development of porcine embryos exposed to OTA. Therefore, OTA exposure induces ER stress and DNA damage via oxidative stress by disrupting PERK/NRF2 signaling activity in the developmental competence of porcine embryos during IVC.

High adult survival in a northern Eurasian Curlew (Numenius arquata) population

Wetland birds such as waders are in decline across Europe. Information on demography is vital for assessing the causes of population declines, but estimates are needed from multiple populations and time periods. We used capture-recapture data from 2013–2022 including 134 individuals to estimate sex-specific apparent adult survival of Eurasian Curlews from a population breeding on agricultural fields in Finland, a stronghold region for this species in Europe. Using the Cormack–Jolly–Seber-model that considers the recapture probability of individuals, we estimated apparent survival of adults to be 0.89 (SE 0.03) for males and 0.92 (SE 0.03) for females. Our estimates of adult survival are slightly higher than those previously estimated from Fennoscandian breeding grounds in 1980s–1990s (0.82–0.88). Thus, our results suggest that adult survival of populations breeding in northern Europe has not declined during the last decades. Our study supports the view that changes in reproductive success is the main cause of decline in the Eurasian Curlew populations.

The American Woodcock Singing Ground Survey largely conforms to the phenology of male woodcock migration

AbstractAmerican woodcock (Scolopax minor; woodcock) are monitored, in part, by counts of displaying male woodcock collected via the American Woodcock Singing Ground Survey (SGS), which suggests long‐term, range‐wide declines in woodcock populations. Data from the SGS have been used extensively to develop conservation plans, direct management actions, and understand causes of decline. To avoid bias, the SGS should be timed to avoid spring migration, and the distribution of survey routes should coincide with woodcock breeding distribution. Our objectives for this research were to evaluate SGS timing with the phenology of male woodcock migration, relate the spatial coverage of the SGS to male woodcock breeding distributions, and explore other sources of variation in woodcock migration timing. We marked 133 male woodcock captured throughout eastern North America with global positioning system (GPS) transmitters during 2019–2022, and compared the timing of their spring migration with the spatiotemporal stratification of the SGS. Most woodcock (74%) completed migration prior to the onset of the SGS. In the northernmost SGS zone, a greater percentage of males (34%) continued migration during the survey window; however, the influence of this mismatch is offset because SGS routes were run more frequently during the second half of the window. Young woodcock completing their first spring migration took 8.6 days longer to do so, on average, compared to adults, and so were more likely to migrate during the SGS window. We found little evidence that timing of migration varied among years. Existing SGS routes cover the majority of male woodcock post‐migratory breeding distribution, with 90% of male woodcock establishing final breeding sites within the spatial coverage of the SGS. Our results confirm the SGS includes some migrating males, with the proportion relative to resident breeding males increasing in more northern survey strata. Our data suggests these errors are unlikely to bias trend estimates at large scales (e.g., within woodcock management regions), but there may be potential for bias at more local scales (e.g., state or provincial population indices).

Widespread learned predator recognition to an alien predator across populations in an amphibian species

Alien predators are a major cause of decline and extinction of species worldwide, since native organisms are rarely equipped with specific antipredatory strategies to cope with them. However, phenotypic plasticity and learned predator recognition may help prey populations to survive novel predators. Here we examine geographical variation in the learning ability of larval spadefoot toads (Pelobates cultripes) to recognize invasive predatory crayfish (Procambarus clarkii). We compare the learning-mediated behavioural responses of tadpoles from six populations across two regions in Spain (central and southern), with different histories of exposure to the presence of the invasive species. Two of the populations showed innate recognition of chemical cues from the invasive crayfish, whereas three of them learned to recognize such cues as a threat after conditioning with conspecific alarm cues. Learning abilities did not differ among southern populations, but they did among central populations. We assessed patterns of genetic variation within and among these two regions through microsatellite markers and found low genetic divergence among the southern populations but greater differentiation among the central ones. We hypothesize that similar responses to the invasive crayfish in southern populations may have arisen from a combination of extended historical exposure to this introduced predator (~ 50 y) and higher levels of gene flow, as they inhabit a highly interconnected pond network. In contrast, populations from central Spain show lower connectivity, have been exposed to the invasive crayfish for a shorter period of time, and are more divergent in their plastic responses.

Reimagining US rare earth production: Domestic failures and the decline of US rare earth production dominance – Lessons learned and recommendations

China has dominated the global production of rare-earth elements (REE) since the 1990s. This market dominance is often described as a Chinese victory over competitors—particularly the US—in a geopolitical contest, since REEs are critical components of numerous advanced technologies, including military systems, that great powers compete to control. However, this geopolitical explanation for recent trends in global REE market fails to account for domestic factors—technical, economic, political, and environmental—that significantly impact the exploitation of geologic resources. This paper assesses the causes of decline in US REE production, which facilitated China's domination of the global market. We show that the failure of the US REE production was primarily caused by domestic factors, including misalignment between the US government and corporate interests. At a time when the China-US competition for REE production is seen not only as an economic contest, but also as a matter of national and international security, we argue that strategic cooperation between China and the US could effectively diversify and improve the resilience of REE supply chains and mitigate economic and national security risks associated with potential future disruptions.

In search of evidence-based management targets: A synthesis of the effects of linear features on woodland caribou

Effective species management relies on evidence-based goals that address the processes influencing population demography. These goals therefore require understanding how stressors affect the species of interest, and the food web within which the focal species is embedded. For woodland caribou, a conservation priority across much of its range, habitat loss and alteration is a primary cause of decline. Governments have identified maximum disturbance targets whereby a maximum of 35% total disturbance provides a 60% likelihood of self-sustaining caribou populations, but targets specific for linear features such as roads and seismic lines — which play a key role in altering ecological processes and are a primary focus for habitat restoration — have not been established. We created a framework to conceptually link stressors (linear features) to caribou declines via ecological mechanisms, and used this framework to guide a literature review to support the development of a linear feature-based management target for Southern Mountain Caribou. Despite the vast amount of research investigating the mechanisms leading to the negative relationship between caribou demography and linear features, our review of 54 peer-reviewed manuscripts and 99 grey-literature reports found little to no evidence of a threshold in these relationships in which to inform a linear feature-based management target for caribou population growth. Most studies evaluated how linear features modify space use of caribou, their predators, and the primary prey of those predators, whereas few mechanistically linked linear features to caribou demography. Our work provides a foundation in which other systems can conceptualize how stressors are linked to species declines, and to support the development of evidence-based management goals.

Early life conditions influence fledging success and subsequent local recruitment rates in a declining migratory songbird, the Whinchat Saxicola rubetra.

Life history traits and environmental conditions influence reproductive success in animals, and consequences of these can influence subsequent survival and recruitment into breeding populations. Understanding influences on demographic rates is required to determine the causes of decline. Migratory species experience spatially and temporally variable conditions across their annual cycle, making identifying where the factors influencing demographic rates operate challenging. Here, we use the Whinchat Saxicola rubetra as a model declining long-distance migrant bird. We analyse 10 years of data from 247 nesting attempts and 2519 post-fledging observations of 1193 uniquely marked nestlings to examine the influence of life history traits, habitat characteristics and weather on survival of young from the nestling stage to local recruitment into the natal population. We detected potential silver spoon effects where conditions during the breeding stage influence subsequent apparent local recruitment rates, with higher recruitment for fledglings from larger broods, and recruitment rate negatively related to rainfall that chicks experienced in-nest. Additionally, extreme temperatures experienced pre- and post-fledging increased fledging success and recruitment rate. However, we could not determine whether this was driven by temperature influencing mortality during the post-fledging period or later in the annual cycle. Brood size declined with hatching date. In-nest survival increased with brood size and was highest at local temperature extremes. Furthermore, nest survival was highest at nests surrounded with 40%-60% vegetation cover of Bracken Pteridium aquilinum within 50 m of the nest. Our results show that breeding phenology and environmental factors may influence fledging success and recruitment in songbird populations, with conditions experienced during the nestling stage influencing local recruitment rates in Whinchats (i.e. silver spoon effect). Recruitment rates are key drivers of songbird population dynamics. Our results help identify some of the likely breeding season mechanisms that could be important population drivers.

Predation of Atlantic salmon across ontogenetic stages and impacts on populations

Managers and stakeholders increasingly ask whether predation is a driving force behind the poor status of many species, and whether predator control is likely to be a successful management action to intervene. We review existing literature on Atlantic salmon Salmo salar predation and predator control, as well as general ecological theory on the role of predation in the life cycle of this iconic fish. Many bird, mammal, and fish predators target salmon at different life stages. In healthy salmon populations, predation is likely compensated for by reduced intraspecific competition during the freshwater stage. There is little evidence that predation alone has been an underlying mechanism for driving salmon populations below conservation limits. However, depending on the predator's response to salmon abundance, predation may keep decimated populations from recovering, even when the actual causes of decline have been removed. Under such a scenario, predation control may contribute to recovery, but there are no strong examples that clearly demonstrate the efficacy of managing predators to recover threatened salmon populations, challenging further applications.

Changes in conception rates, not in pregnancy-related behaviour, likely caused decline in preterm births during the first year of the COVID-19 pandemic.

Changes in conception rates, not in pregnancy-related behaviour, likely caused decline in preterm births during the first year of the COVID-19 pandemic.

국내 꿀벌에서 Lotmaria passim 검출

Apis mellifera, also known as the western honey bee, is one of the most important pollinators of flowering plants, including many agricultural crops. In Korea, the number of honey bee pollinations have been fluctuating in recent years. Several honey bee parasites have been presumed as probable causes of decline. Lotmaria passim is the most virulent trypanosome parasite which usually infects the A. mellifera intestine. After first report in 1911, L. passim widely present in South America and Europe including Uruguay, Argentina, Chile and Spain. However, the presence of this virulent trypanosome is not reported in Korea before. The aim of the present work was to provide the evidence of detection of the L. passim from A. mellifera in Korean agriculture. A. mellifera from three sites; Gwangju, Yangpyung and Toechon was ground with liquid nitrogen and mRNA was extracted. Quantitative real-time PCR (qPCR) was used to investigate the presence of L. passim nucleic acid. The amplification products were also sequenced and analyzed. L. passim was detected from honey bee in Yangpyung. PCR products were sequenced and the nucleotide sequence was aligned to the complete L. passim sequence from NCBI database, and the sequence were revealed 100% identity. The honey bee parasitic trypanosome L. passim was found in the Korea honey bee first time and should be considered as a potential contributor of honey bee infectious disease in Korea.